This specification prescribes requirements for the classification of brazing filler metals for brazing and braze welding. It includes brazing filler metals for brazing with or without a flux and in all protective atmospheres for various applications, including those for vacuum service.¹ The prefix "RB" indicates that the brazing filler metal is suitable for use both as brazing rod for braze welding and as a brazing filler metal.

¹ Filler metals for vacuum service are for devices operating in vacuum service, regardless of the atmosphere used in making the joint.